Method of microalgal biomass processing for high-value chemicals production, the resulting composition of butyrogenic algal slowly fermenting dietary fiber, and a way to improve colon health using a slowly fermenting butyrogenic algal dietary fiber

Abstract

A method to process microalgae biomass and produce high-value chemicals from microalgae biomass is disclosed. The method uses the same biomass cells to extract more than one component such as lipids, water-soluble chemicals, carotenoids, polysaccharides and algae meal. The method is a sequence of physical and chemical treatments. Water soluble polysaccharides produced by the method exhibit properties of low viscosity at low shear thinning. A method for extracting dietary fiber from microalgal biomass is disclosed. Compositions of water-soluble polysaccharides that are fermented slowly by colon microbiota with less gas production than commercial dietary fiber FOS are disclosed. The present inventions described herein provide a method of improving colon health by increasing butyrate during a microalgal dietary fiber fermenting process by colonic microbiota.

Description

CROSS REFERENCE[0001]This application claims the benefit of U.S. Provisional Application No. 62 / 547,967, filed Aug. 21, 2017, and U.S. Provisional Application No. 62 / 549,469, filed Aug. 24, 2017. This application expressly incorporates by reference each of these provisional patent applications.FIELD[0002]In one aspect, the present invention is related to a method of extracting chemicals from microalgal biomass such as Botryococcus braunii. In another aspect, the present invention is related to the use of a water-soluble polysaccharide, extracted from microalgal biomass such as Botryococcus braunii, to improve and maintain colon health.BACKGROUND[0003]Food security and energy for transportation are global concerns due to increased population and decreased fossil fuel resources. Countries that produce and export oil are not even safe from the depletion of oil and the socioeconomic consequences. Land crops are an alternative to fossil fuels and are a source of oil for biofuels like bio...

AI Technical Summary

Benefits of technology

[0052]The present research project was initiated to develop a commercially viable microalgae biorefinery using a wild B. braunii strain. The production of high-value chemicals could be a sustainable alternative in the biorefinery feasibility. The design of a processing line is needed to produce high-value chemicals in a way that will make the microalgae biorefinery a viable industry because current methods for biomass production and oil extraction cost too much to compete with the fossil fuel industry. The major challenge was how to develop a method that allows for selective extraction of each high-value chemical from the same cell at low cost. The project started with the development of microalgae strains with high biomass and oil yield that tolerate environmental changes. In meantime, additional project strategy includes exploring all major cell components that may have some commercial value.

[0058]In one embodiment of the invention, the present disclosure teaches an extraction method to isolate all the high-value components of the cell selectively. Another embodiment illustrates a way to extract microalgal water-soluble polysaccharides with relatively, low viscosity at low shear stress.

[0059]Shear thinning and viscosity are temperature dependent. The relatively low viscosity at low shear stress properties allows these novel polysaccharides to be easily mixed with other ingredients, pumped, and handled during processing and as an ingredient or end product. Thus in further embodiments, water-soluble polysaccharides with relatively, low viscosity at low shear stress are used as food and beverages ingredients and as supplements with mouthfeel characteristics.

[0060]Additional embodiments described herein provide a method for improving colon health by increasing short chain fatty acid concentration such as butyrate in the colon via the use of a slowly fermenting microalgal dietary fiber. The process results in an increase in the SCFAs butyric acid (also called butyrate) and propionic acid (also called propionate). This increase is associated with a decrease in acetic acid (also called acetate) production. Butyrate production reached 40 percent after 12 hours of fermenting the microalgal dietary fiber, with 32 percent propionate and acetate as illustrated in FIGS. 9 and 10. Butyrate is used as an energy source by epithelial cells of the colon, colonocytes, and retards proliferation of malignant colonic cells.

[0064]In one embodiment of the present invention, water-soluble dietary fibers are extracted from microalgae. The novel dietary fibers have physical and chemical proprieties that make the microalgal extract a good ingredient for the food, beverages, supplement, cosmetic, animal feed and pharmaceutical industries. The water-soluble dietary fibers are easy to mix with other ingredients. The water-soluble dietary fibers have shear stress proprieties which change their viscosity under stress. The water-soluble dietary fibers can be used as an ingredient in beverages at a level of 10 to 20 percent (weight / volume) etc. Moreover, the water-soluble dietary fibers have potential health benefits, especially improving colon health.

[0068]The microalgal dietary fibers promote the development of butyrogenic colon bacteria and significantly increase the level of butyrate production. Butyrate is one of the most important metabolites among the produced SCFA in the present disclosure. Butyrate is used as a major energy source for colonocytes, it promotes colonic epithelial tissue regeneration and proliferation, it exhibits anti-inflammatory properties, it is involved in gene expression, and it initiates apoptosis in malignant and cancer cells in the colon. Butyrate has an anti-proliferation behavior.

Problems solved by technology

Unfortunately, the composition does not have the appropriate and necessary physical properties to have many commercial applications in food, beverages, etc.

The major challenge was how to develop a method that allows for selective extraction of each high-value chemical from the same cell at low cost.

This type of dietary fiber can be developed by chemical modification, but it is a costly operation.

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